The present invention relates to a package for storing and dispensing flowable components. In particular, the present invention relates to a package for storing separate flowable components, and dispensing the flowable components in a substantially simultaneous manner.
A number of liquid and semi-liquid compositions are made from two or more flowable components that are typically not mixed together until immediately prior to use. For example, certain adhesives such as epoxies are sold in packages that initially keep components of the adhesive separated from each other. Whenever such adhesives are needed for use, the components are mixed together and a chemical reaction between the two components begins. After the components are mixed, the composition is applied to the work site before the composition unduly hardens.
A number of packages have been proposed over the years for separately containing and storing components of multiple-component compositions. Examples of commonly-used packages for multiple-component compositions include dual-chamber cartridges, static mixers, and applicator assemblies. However, such packages are not sufficient for dispensing multiple-component compositions in a variety of applications, particularly where only a relatively small amount of composition is needed. In those instances, large portions of the initial flowable components may remain in the cartridge after a sufficient amount has been taken for the work at hand.
Moreover, when packages are used in health care fields such as dentistry, the user must take care to avoid cross-contamination between patients in offices where the composition from a single package is used in multiple procedures among different patients. The issue of cross-contamination can be addressed by proper handling of the dispensing assembly to ensure that disinfection of the cartridge, static mixer, and applicator assembly is accomplished as needed. However, inadequate attention to proper disinfection and handling techniques of the assembly may increase the risk of transferring an infectious disease from one patient to another.
As such, single use packages have been developed for storing and dispensing of multiple-component compositions. Such packages may be formed, for example, by sheets of flexible material having initially separate chambers that receive the components. When the composition is needed, the flexible sheets are squeezed together to decrease the volume in the chambers and direct the components along a path for mixing and dispensing. However, a common issue with such packages is the number of steps required to obtain the multiple-component composition. Generally, the flowable components are required to be dispensed into a series of adjacent chambers, which commonly results in an undesirable backflow of the components into previously dispensed chambers. Backflow reduces the total amount of the available composition, and may potentially offset the relative amounts of the flowable components. Accordingly, there is a need in the industry for packages that store and dispense multiple-component compositions that are efficient to use and easy to manufacture.